| Bemisia tabaci is a serious pest of vegetables and crops worldwide. The most damaging and predominant Bemisia tabaci in China are the B and Q, and they both are vectors of tomato yellow leaf curl virus(TYLCV). Recent years, Q has replaced B in many areas of China, and subsequently TYLCV break out in many places. The transmission and dispersal capacity of vectors usually influence the spread of plant viruses, and female and male insects tend to have different abilities in transmitting virus. No previous study, however, has compared the acquisition, retention, and transmission characteristics of TYLCV by B and Q females and males. In the present study, we quantitatively compared the acquisition, retention, and transmission of TYLCV by both sexes of B and Q. We also determined the factors influencing the virus transmission from the the angles of whiteflies feeding behavior, the composition of symbionts and the field investigation. The main results are as follows:(1)We compared the capability of acquisition, retention, and transmission ability of TYLCV by B and Q. We found that TYLCV attained maximal viral loads in all whiteflies after 48-h, and the female Q is more efficient in virus acquisition than male Q, female B and male B. The virus titer decreased gradually in all whitefly populations but was always greater in Q females than in the other combinations. Transmission was significantly higher for Q females than for the other three populations.(2)The detection of endosymbionts in female B, male B, female Q and male Q biotype B. tabaci populations was conducted. The results showed that in female Q the content of Hamiltonella was much high than male Q, female B and male B.(3)The effects of whiteflies feeding behavior on virus transmission were determined. The results showed that the female whiteflies feed better than males, and female Q feed better in phloem sap ingestion parameters than male Q, female B and male B.(4) Whitefly distribution in Beijing area were investigated. We randomly selected whiteflies of five places in tomato farm in Beijing, and we identified that all the whiteflies are Q, and we also found the female proportion is higher than male in the field.In summary, Q females are more efficient than Q males, B female and B males at TYLCV acquisition and transmission, and the content of Hamiltonella Q female was significantly higher than other whitefly populations. In addition, feeding behavior Q females exhibit a stronger advantage than other populations. This may be an important cause of field tomato yellow leaf curl virus outbreak. Meanwhile, the results can provide reference for field control of tomato yellow leaf curl virus transmitted by whiteflies, which has a very important significance in virus prevention. |
